LigHtEmUp01

so i had my car getting a dyno tune and within a few pulls he tells me its leaning out and that he kept giving it nore fuel and it was still leaning out. im lost here. i have stock injectors and fuel pump. i replaced the filter and it ran a little better but i dont know what to do next. it also had a missfire that i thought was due to incorrect timing/fuel but it was a plug and i ran it on the dyno with the miss, since i did plugs it runs like its stock and slow. so what do yall think?

the_merv

iTrader: (88)

You might need to upgrade the Injectors..

SS RRR

iTrader: (2)

One possibility is there is too much unburnt fuel getting past the O2's tricking them into thinking the mixture is lean. Stock injectors can handle the average heads/cam setup that is producing high 300rwhp figures.

LigHtEmUp01

that coule be true because before the tune i thought it ran rich and he told me it was lean. if it is that case what do i do?

boosted LT1

iTrader: (3)

Get a cable and collect data so you aren't guessing. Datamaster gives ~20 free collections and if you collect long data pull and analyze and make corrections you will know and fix what is wrong without buying more than the cable.

Besides tune: power to pump can be low, pump can be weak, kinked fuel lines, bad Fuel pressure regulator, fuel filter partly clogged, etc etc etc...I would start by checking fuel pressure. A miss will show up as lean do the obvious and cheapest fixes first...

Good luck

*02WS6TURK*

iTrader: (13)

+1 I would look into some different injectors.

Big Al

iTrader: (1)

Can someone tell me how he "kept giving it more fuel?"

Al

LSWHO

iTrader: (1)

Adjusting the afr in the tune.

LSWHO

iTrader: (1)

You say this, but I was at 93% cam only on stock injectors.

jaycenk

iTrader: (1)

Were those heads milled at all when they were off?

qc97z

iTrader: (9)

Injectors are too small, IMO. If I was doing heads/cam the FIRST thing I would do is get ahold of a Walbro 255, hotwire kit, and 30# injectors.

SS RRR

iTrader: (2)

You must have been making massive power for being cam only. I was at 370rwhp with stock injectors and pump running 12.2 to 12.0 at 115mph and the fuel curve was bueno. Ran it like that for nearly 70K miles with original pump and injectors so yes, I say that. I highly doubt the op's problem is fuel delivery related unless the pump is going south.

LSWHO

iTrader: (1)

I'm not saying you're wrong, I'm just saying that it sounds like it's not as easy as you make it sound.

SS RRR

iTrader: (2)

It was pretty easy. I bolted on heads. I then stabbed the cam. I then drove car from Keller, TX to Tulsa, OK and had Ed Wright dyno tune it. Easy peasy lemon squeezy. The only huge challenge I had with this venture is cleaning the innards of an armadillo splattered all over the front sway bar and k-member that I hit on the way to Ed's shop.

LSWHO

iTrader: (1)

Easy for you? yes.
Easy for everybody? no.

I'm at 75% duty cycle with 30# injectors, at 6200rpm, cam only with a 13.0 AFR. I prefer to stay under 80% duty cycle. If I had stock injectors I'd be 90%ish with a 13.0 AFR. I was 93% with the 11.8ish AFR.

Again, cam only.

Sure, I could run heads/cam on stock injectors, but close to 100% duty cycle is stupid IMO.

Not every LT1 came with Super injectors, I guess.

SS RRR

iTrader: (2)

Ed Wright had no problem with it. I had no problem with it. You calling Ed Wright stupid? The car managed fine for tens of thousands of miles being shifted to 6200rpm almost daily. There are many who have done the same thing long before you decided to think you understood tuning input with opinions that mattered.

LSWHO

iTrader: (1)

Oh my god stfu.

I'm haven't called ed anything. I didn't call you anything either.

It's truly pathetic that an old man acts like you do.

Do you not realize that cars are different in different environments and what works for you doesn't work for everybody else? Your generic blanket statements are stupid and foolish and I can bet Ed would agree with me.

According to you nearly 100% duty cycle is totally safe. I doubt Ed would agree, but hell I don't know anything apparently.

Generic blanket statements. That's the key to life.

Hell with your insight maybe I could have a car 10mph slower than it should be too. You are an LT1 whiz. I think we all agree.

Grow the hell up, you are pathetic for being so old and acting like this.

Everybody else in this thread disagrees with your injector "knowledge" by the way. (you know the guys that have faster cars than you?)

SS RRR

iTrader: (2)

Don't be mad.
Sorry. It's just that I can't take you seriously. I think it's all the crying you do whenever your intellect is challenged.
Apparently. Here's another blanket statement that has worked well since before.. well nevermind.
Flywheel hp * .07 = injector flow rate
As far as my age, when you get into your 40's I'll let you become a self-loathing, pouty, boring old ****.

P.S. So my car is now supposed to run in the 130mph range? Now you are just being an overly dramatic tard. Shush.

the_merv

iTrader: (88)

Things never change..
Adjusting the VE Table in the Tune.
This. Do it.

SS RRR

iTrader: (2)

Yes OP. Instead of checking your fuel pressure to see if the pump is going out, just replace it. Instead of checking other possible reasons for a lean condition do the smart thing and throw parts at it hoping it will fix your problem. Best advice ever.